Connecting member for a fast-fit safety coupling

ABSTRACT

A connecting member ( 4 ) for a fast-fit safety coupling ( 1 ), having a tubular main member ( 10 ) connectable to a first conduit ( 2 ) for conducting pressurized fluid; a valve member ( 11 ) fitted inside the main member ( 10 ) to slide axially between a first work position separating the first conduit ( 2 ) in fluidtight manner from the outside, and an open second work position; first retaining means ( 18 ) for releasably connecting an endpiece ( 5 ) of a second conduit ( 3 ) to the valve member ( 11 ); second retaining means ( 17 ) for releasably connecting the valve member ( 11 ), in the second work position and connected to the endpiece ( 5 ), to the main member ( 10 ); and control means ( 70, 71, 72, 54 ) for disconnecting the connecting member ( 4 ) and the endpiece ( 5 ). The control means have a first actuating member ( 70 ) fitted in angularly fixed manner to the valve member ( 11 ) and movable axially, with respect to the valve member and upon deactivation of the second retaining means, to release the first retaining means ( 18 ); a second actuating member ( 71 ) connected in axially fixed, rotary manner to the valve member ( 11 ); and cam transmission means ( 72 ) for converting rotation of the second actuating member ( 71 ) into axial displacement of the first actuating member ( 70 ) to release the endpiece ( 5 ).

TECHNICAL FIELD

[0001] The present invention relates to a connecting member for afast-fit safety coupling for fluidtight connection of twopressurized-operating-fluid, in particular compressed-air or gas,conduits.

BACKGROUND ART

[0002] Known fast-fit non-safety couplings substantially comprise anormally substantially cylindrical connecting member connected to afirst of the conduits; and a normally substantially cylindrical endpiececonnected to a second of the conduits and which fits releasably into anengaged position inside the connecting member.

[0003] The connecting member comprises a hollow main member connected tothe first conduit; a slide valve member fitted to slide axially insidethe main member; a cylindrical helical spring interposed between themain member and the valve member, and which exerts axial pressure on thevalve member to keep it in a first work position isolating the firstconduit in fluidtight manner from the outside; and releasable stop meansfor retaining the endpiece of the connecting member in the engagedposition, wherein the endpiece exerts opposite pressure on the valvemember to overcome the pressure of the spring and so keep the valvemember in a second work position permitting fluid flow between the firstand second conduit.

[0004] A drawback of such couplings is that, when disconnected, theendpiece, pushed by the pressure of the fluid and the return pressure ofthe spring, tends to be released violently from the connecting memberand possibly strike and, at times, injure the operator, or at leastdamage any nearby machinery or other objects.

[0005] To eliminate the above drawback, fast-fit safety couplings havebeen devised, as described, for example, in international PatentApplication n. WO99/19657 filed by the present Applicant, and whereinthe main member of the connecting member comprises axially spaced firstand second releasable stop means. More specifically, the first stopmeans cooperate with the endpiece to lock it in the engaged position;and the second stop means cooperate with the endpiece to keep it, uponrelease of the first stop means and when disconnected from theconnecting member, in a withdrawn safety position, wherein the endpieceis mechanically connected to the main member, and the valve member isset to the first work position isolating the first conduit in fluidtightmanner and wherein the operating fluid inside the coupling, between thefirst and second conduit, is allowed to flow out.

[0006] The first stop means are interposed between the main member andthe valve member, and the second stop means comprise releasableretaining means carried by the valve member and which cooperate with theendpiece to make it integral with the valve member as the endpiece movesbetween the withdrawn safety position and the forward engaged position.

[0007] More specifically, the second stop means comprise a selectionring nut, which is carried by the valve member, is normally maintainedby a spring in a predetermined axial position on the valve member, andcan be pushed axially—in opposition to the spring and in the oppositedirection to that in which the valve member moves from the second to thefirst work position—to release the retaining means.

[0008] Though in many respects extremely advantageous and safe, theabove solution still leaves room for improvement.

[0009] In particular, in the event the user, when releasing the firststop means and so moving the valve member from the second to the firstwork position, inadvertently grips and prevents the selection ring nutfrom moving integrally with the valve member, the retaining means may bereleased simultaneously, thus resulting in violent release of theendpiece from the connecting member. Axially retaining the selectionring nut with respect to the valve member, in fact, results in relativemovement of the selection ring nut with respect to the valve member inthe retaining means release direction.

DISCLOSURE OF THE INVENTION

[0010] It is an object of the present invention to provide a connectingmember for a fast-fit safety coupling, designed to eliminate the abovedrawback typically associated with the aforementioned known safetycouplings.

[0011] According to the present invention, there is provided aconnecting member for a fast-fit safety coupling, as claimed in claim 1.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] A preferred, non-limiting embodiment of the present inventionwill be described by way of example with reference to the accompanyingdrawings, in which:

[0013]FIG. 1 shows an axial section of a fast-fit safety coupling havinga connecting member in accordance with the present invention, and anendpiece connected to the connecting member in the engaged position;

[0014]FIG. 2 shows a side view of the FIG. 1 connecting member andendpiece in the disconnected position;

[0015]FIG. 3 shows a larger-scale axial section of connection of theFIG. 1 connecting member and endpiece;

[0016]FIG. 4 shows an axial section of the FIG. 1 coupling in the safetyposition;

[0017]FIG. 5 shows a section along line V-V in FIG. 1;

[0018]FIG. 6 shows a smaller-scale section along line VI-VI in FIG. 3;

[0019]FIG. 7 shows a smaller-scale section along line VII-VII in FIG. 3;

[0020]FIG. 8 shows a section along line VIII-VIII in FIG. 3;

[0021]FIG. 9 shows an axial section of the FIG. 1 coupling as theendpiece is disconnected fully from the connecting member;

[0022]FIG. 10 shows a partial, larger-scale, exploded view inperspective of two ring nuts of the FIG. 1 connecting member for fullydisconnecting the endpiece from the connecting member;

[0023]FIGS. 11a and 11 b show developed plan views of mating face edgesof the FIG. 10 ring nuts in the FIG. 9 position and FIGS. 1, 3 and 4positions respectively;

[0024]FIG. 12 shows a partial axial section of a possible variation ofthe FIG. 1 connecting member.

BEST MODE FOR CARRYING OUT THE INVENTION

[0025] With reference to FIGS. 1, 3, 4 and 9, number 1 indicates as awhole a fast-fit safety coupling for fluidtight connection of twoconduits 2, 3 (FIG. 3) for conducting pressurized operating fluid, inparticular compressed air or gas.

[0026] Coupling 1 has a longitudinal axis A, and comprises a connectingmember 4 in accordance with the present invention, substantiallycylindrically symmetrical with respect to axis A, and connectable toconduit 2; and an endpiece 5 (known and not forming part of the presentinvention) which is also substantially cylindrically symmetrical, isconnected to conduit 3, and is connectable releasably to connectingmember 4.

[0027] With reference to FIGS. 1 to 4 and FIG. 9, endpiece 5 issubstantially tubular and of axis A, and comprises a cylindrical mainportion 6 connected, in use, to conduit 3 and having an outer annularretaining groove 7, and a cylindrical free-end portion 8 smaller indiameter than and connected to portion 6.

[0028] With reference to FIGS. 1 to 9, connecting member 4 comprises anouter main member 10, which is substantially tubular of axis A and hasan externally threaded sleevelike end portion 10 a connected to conduit2; a slide valve member 11 mounted to slide axially inside main member10 and defining, with end portion 10 a of main member 10, asubstantially cylindrical chamber 12 of axis A communicating, in use,with conduit 2; a cylindrical helical spring 13 of axis A, which ishoused inside main member 10 and exerts axial pressure on valve member11 to keep it in a first work position (FIGS. 3 and 9) in which valvemember 11 rests against an annular, radially inner projection 14 of mainmember 10 and separates chamber 12 and conduit 2 in fluidtight mannerfrom the outside; a releasable first stop mechanism 15 defining, in use,a forward engaged position (FIG. 1) of endpiece 5 inside connectingmember 4, wherein endpiece 5 exerts opposite pressure on valve member 11to overcome the pressure exerted by spring 13 and so keep valve member11 in a second work position (FIG. 1) permitting fluid flow betweenconduits 2 and 3; and a releasable second stop mechanism 16 whichcooperates with endpiece 5 to keep it, upon release of stop mechanism 15and when disconnecting endpiece 5 from connecting member 4, in awithdrawn safety position (FIG. 4) wherein endpiece 5 is connectedmechanically to connecting member 4, and valve member 11 is set to thefirst work position and allows the operating fluid between projection 14and conduit 3 to flow out.

[0029] Stop mechanism 15 comprises releasable connecting means 17between main member 10 and valve member 11; and stop mechanism 16comprises releasable retaining means 18 carried by valve member 11 andwhich cooperate with groove 7 on endpiece 5 to make endpiece 5 integralwith valve member 11 between the withdrawn safety position and theforward engaged position.

[0030] With particular reference to FIG. 3, projection 14 has acylindrical surface 20 of axis A defining a sliding seat for valvemember 11, and is defined, towards conduit 2, by a truncated-cone-shapedsurface 21 of axis A with its concavity facing conduit 2, and, on theopposite side, by a circular annular surface 22 also of axis A anddefining an axial stop for spring 13.

[0031] Chamber 12 is thus defined by a radially inner, cylindricalsurface 23 of end portion 10 a of main member 10, by surface 21 ofprojection 14, and by valve member 11.

[0032] With reference to FIGS. 1, 3, 4 and 9, valve member 11 issubstantially elongated-cup-shaped of axis A, and is defined by adisk-shaped end wall 25, and by a substantially cylindrical lateral wall26 defining an inner cavity 27 and connected to disk-shaped wall 25 by ashort cross portion 28 about which spring 13 is wound, and which, in thesecond work position of valve member 11, permits fluid flow betweenchamber 12 and cavity 27.

[0033] More specifically, disk-shaped wall 25, together with crossportion 28, is engaged in axially sliding manner inside cylindricalsurface 20 of projection 14, and is fitted externally with a sealingring 29, of axis A, which, in the first work position of valve member11, rests against surface 21 of projection 14 to separate chamber 12 andconduit 2 from cavity 27, and therefore from the outside, in fluidtightmanner.

[0034] Lateral wall 26 is defined by a number of substantiallycylindrical portions 30, 31, 32 decreasing in outside diameter towardscross portion 28.

[0035] Of portions 30, 31, 32 of lateral wall 26, portion 30 defines,immediately adjacent to cross portion 28, an annular stop shoulder 33for spring 13 and axially facing surface 22 of projection 14. Morespecifically, portion 30 is defined by two cylindrical portions 34, 35,of which portion 34 is contiguous to shoulder 33 and smaller in diameterand length than portion 35.

[0036] A sealing ring 36 is interposed between portion 30 of valvemember 11 and main member 10, and engages a respective annular groove onmain member 10. In the first work position of valve member 11, ring 36is positioned between projection 14 and portion 34 of portion 30 toallow operating fluid to flow out from cavity 27; whereas, in the secondwork position of valve member 11, ring 36 is compressed betweenprojection 14 and portion 35 of portion 30 to provide a fluidtight sealbetween main member 10 and valve member 11.

[0037] Portions 31 and 32 of lateral wall 26 are located one after theother as of portion 30 and away from disk-shaped wall 25.

[0038] A cylindrical sleeve 40 is housed in axially sliding mannerinside portion 32 of lateral wall 26, and is loaded axially by acylindrical helical spring 41 housed inside cavity 27 of valve member 11and interposed between one end of sleeve 40 and an annular shoulder 42formed on a radially inner surface of portion 31 of lateral wall 26. Asealing ring 43, housed in an inner annular groove on portion 32 oflateral wall 26, is compressed between valve member 11 and end portion 8of endpiece 5, in the forward engaged position of endpiece 5, anddefines an axial stop preventing sleeve 40 from being expelled fromcavity 27 by spring 41 in the absence of endpiece 5.

[0039] When inserted inside cavity 27 of valve member 11, end portion0.8 of endpiece 5 exerts axial pressure on sleeve 40 in opposition toand greater than that of spring 41 to move sleeve 40 axially towardsdisk-shaped wall 25.

[0040] Portion 32 of lateral wall 26 has an outer annular flange 45, onthe peripheral edge 46 of which are formed two parallel flat portions 47(FIG. 7) located on diametrically opposite sides of axis A and whichcooperate in sliding manner with respective flat portions 48 on mainmember 10 to define a prismatic coupling between, and prevent relativerotation of, main member 10 and valve member 11.

[0041] With reference to FIGS. 1 to 6 and FIG. 9, connecting means 17comprise a push-button member 51 carried by main member 10 and movable,perpendicularly to axis A and inside a respective transverse seat 52 onmain member 10, between a coupling position (FIGS. 1 and 5), in which itengages an outer annular groove 53, formed in portion 31 of lateral wall26 of valve member 11, to define the second work position of valvemember 11 and, hence, the engaged position of endpiece 5, and a releaseposition (FIGS. 3, 4, 6, 9), in which it is detached from groove 53.

[0042] More specifically, push-button member 51 comprises a dome-shapedactuating portion 54 having a substantially rectangular outer edge andhoused loosely inside an outer recess 55, of corresponding shape, formedin main member 10 and communicating with seat 52; and a substantiallyU-shaped guillotine portion 56, which projects from actuating portion54, is housed in sliding manner inside seat 52, and is fitted radiallyloosely to the outside of portion 31 of lateral wall 26 of valve member11. More specifically, guillotine portion 56 comprises two straight,parallel branches 57 projecting from opposite sides of actuating portion54; and an arc-shaped latch portion 58 connecting branches 57 and whichcooperates with the outer surface of portion 31 of lateral wall 26 ofvalve member 11 and with groove 53.

[0043] Push-button member 51 is loaded, perpendicularly to axis A, by aspring 59 interposed between a bottom surface of recess 55 and actuatingportion 54, so that latch portion 58 of guillotine portion 56 ismaintained permanently contacting the outer surface of portion 31 ofvalve member 11 on the diametrically opposite side to actuating portion54.

[0044] With reference to FIGS. 1, 3, 4, 8 and 9, retaining means 18comprise two bars 60, which are housed in respective transverse grooves61 formed in portion 32 of lateral wall 26 of valve member 11, ondiametrically opposite sides of axis A, and slide, inside grooves 61 andto and from axis A, between a first work position (FIGS. 1, 3, 4 and 8)in which respective intermediate portions 62 project partly insidecavity 27 and engage groove 7 on endpiece 5 to mechanically connectvalve member 11 and endpiece 5, and a second work position (FIG. 9) inwhich intermediate portions 62 are located between the radially innerand outer surfaces of portion 32 of lateral wall 26 of valve member 11to permit release of endpiece 5 from valve member 11.

[0045] More specifically, grooves 61 have respective axes parallel toeach other and perpendicular to axis A, and are each defined by parallelsides sloping with respect to axis A and diverging with respect to thecorresponding sides of the other groove 61 towards disk-shaped wall 25.

[0046] Each bar 60 also has opposite ends 64 projecting outwards withrespect to portion 32 of lateral wall 26 of valve member 11.

[0047] Retaining means 18 also comprise a push ring 65 fitted in axiallysliding manner about portion 32 of lateral wall 26 of valve member 11,and maintained resting against ends 64 of bars 60 by a cylindricalhelical spring 66 wound coaxially about portion 32 and resting againstflange 45. In the absence of external loads, bars 60 are maintained inthe first work position by spring 66 and push ring 65.

[0048] An important aspect of the present invention (FIGS. 1, 3, 4, 8,9, 10, 11 a, 11 b) is that stop mechanism 16 also comprises a firstactuating ring nut 70 fitted in angularly fixed, axially sliding mannerto portion 32 of lateral wall 26 of valve member 11 inside main member10, and cooperating with ends 64 of bars 60 on the opposite side withrespect to push ring 65; a second actuating ring nut 71 operated fromthe outside and fitted in axially fixed, rotary manner to portion 32;and cam transmission means 72 interposed between ring nuts 70 and 71 andfor converting rotation of ring nut 71 about axis A into axialtranslation of ring nut 70 in opposition to spring 66, so as to movebars 60 into the second work position and release bars 60 from groove 7on endpiece 5.

[0049] With particular reference to FIGS. 8 and 10, a radially innersurface of ring nut 70 has a number (four, in the example shown) offirst radial grooves 73 equally spaced angularly about axis A andengaged in sliding manner by respective outer radial projections 74 onportion 32 of lateral wall 26 of valve member 11. Similarly, a radiallyouter surface of ring nut 70 has a number (four, in the example shown)of second radial grooves 75 equally spaced angularly about axis A andengaged in sliding manner by respective inner radial projections 76 onmain member 10.

[0050] With reference to FIGS. 1, 3, 4, 9 and 10, ring nut 71 comprisesan inner annular projection 77 fitted in rotary manner to portion 32 oflateral wall 26 of valve member 11 and locked axially, on one side, byprojections 74 and, on the opposite side, by a retaining ring 78 fittedto the outside of portion 32.

[0051] A radially outer surface of ring nut 71 has four radial grooves79 equally spaced angularly about axis A and engaged by projections 76in the second work position of valve member 11 or in the forward engagedposition of endpiece 5, so as to prevent ring nut 71 from beingactivated before push-button member 51 is set to the release position.The axial length of projections 76 is such as to permit release ofgrooves 79 of ring nut 71 in the first work position of valve member 11.

[0052] With particular reference to FIGS. 10 and 11, cam transmissionmeans 72 are defined by respective contoured face surfaces 80, 81 ofring nuts 70, 71, mating with each other and having complementary edges.More specifically, face surface 80 is defined by a number (four, in theexample shown) of troughs 82 having, in developed plan view, a V-shapedouter edge and alternating with respective flat portions 83; while facesurface 81 is defined by a number of crests 84 having edgescorresponding in shape to those of troughs 82 and also alternating withrespective flat portions 85.

[0053] Assembly of coupling 1 will be described as of an initialconfiguration (FIG. 2) in which endpiece 5 is fully withdrawn fromconnecting member 4; valve member 11 is in the first work position (FIG.3) separating chamber 12 from cavity 27 in fluidtight manner by means ofring 29; push-button member 51 is in the release position; sleeve 40 ispushed by spring 41 against sealing ring 43; bars 60, subjected to theaction of spring 66 and push ring 65, are in the first work position, inwhich intermediate portions 62 project inside cavity 27; and troughs 82of face surface 80 of ring nut 70 are engaged by respective crests 84 offace surface 81 of ring nut 71.

[0054] Endpiece 5 is fitted to connecting member 4 by simply insertingendpiece 5 in one movement inside cavity 27 of valve member 11. At thisstage, on contacting main portion 6 of endpiece 5, the outside diameterof which is substantially equal to the inside diameter of portion 32 oflateral wall 26 of valve member 11, bars 60 are pushed into the secondwork position. As soon as groove 7 in endpiece 5 reaches bars 60, theseare pushed by spring 66 along respective grooves 61 back into the firstwork position to engage groove 7 and so mechanically connect endpiece 5and valve member 11 (FIG. 4).

[0055] At this point, end portion 8 of endpiece 5 comes into contactwith sleeve 40 and pushes it towards disk-shaped wall 25 of valve member11 to fully compress spring 41, which is less stiff than spring 13. Asendpiece 5 continues to be pushed axially inside connecting member 4,valve member 11 moves, integrally with endpiece 5, from the first to thesecond work position, thus compressing spring 13 and gradually movingring 29 away from the surface of projection 14, so that chamber 12communicates with cavity 27 via cross portion 28 of valve member 11, andsealing ring 43 is compressed between end portion 8 of endpiece 5 andportion 32 of lateral wall 26 of valve member 11.

[0056] As groove 53 in valve member 11 reaches guillotine portion 56,the thrust exerted by spring 59 causes pushbutton member 51 to slideinside seat 52 on main member 10 and click into the coupling positioninside groove 53, thus locking valve member 11 in the second workposition permitting fluid flow between conduits 2 and 3, and definingthe forward engaged position of endpiece 5 inside connecting member 4(FIG. 1).

[0057] At this stage, the operating fluid from conduit 2 flows throughcross portion 28, projecting inside chamber 12, and through cavity 27and sleeve 40 into endpiece 5 and conduit 3. In this configuration,rings 36 and 43 ensure perfect outward sealing of coupling 1.

[0058] Endpiece 5 is disconnected from connecting member 4 by actingseparately and successively on push-button member 51 and actuating ringnut 71. More specifically, in the engaged position of endpiece 5, ringnut 71 is locked axially to valve member 11 between projections 74 andretaining ring 78, and is prevented from being rotated by radialprojections 76 on main member 10 engaging grooves 79 (FIG. 1).

[0059] Pressure must therefore be applied, perpendicularly to axis A, onactuating portion 54 of push-button member 51 to release guillotineportion 56 from groove 53. At which point, the pressure of spring 13 andthe pressurized fluid pushes valve member 11 from the second to thefirst work position, in which, ring 29 contacts surface 21 of projection14, so that chamber 12, and therefore conduit 2, is separated from therest of coupling 1. At the same time, ring nuts 70, 71 are movedintegrally with valve member 11 and slide axially with respect to mainmember 10. At this stage, endpiece 5 is still secured to valve member 11by bars 60 engaging groove 7.

[0060] Upon valve member 11 reaching the first work position, grooves 79on ring nut 71 are released from projections 76 on main member 10, andring 43 is positioned between the small-diameter portion 34 of valvemember 11 and the radially inner surface of main member 10, thusenabling the operating fluid between projection 14 and conduit 3 to flowout.

[0061] Only at this point can actuating ring nut 71 be rotated in eitherdirection about axis A; crests 84 of face surface 81 of ring nut 71slide along the sloping sides of corresponding troughs 82 of facesurface 80 of ring nut 70 up to flat portions 83; and, at the same time,ring nut 70 moves axially towards disk-shaped wall 25, and moves bars 60into the second work position in opposition to spring 66, thus releasingendpiece 5, which is detached in perfectly controlled manner owing tothe absence of any pressure inside cavity 27 of valve member 11 (FIG.9).

[0062] The variation in FIG. 12 shows a connecting member 4′, which issimilar to connecting member 4, and the component parts of which areindicated, where possible, using the same reference numbers as for thecorresponding parts of connecting member 4.

[0063] Connecting member 4′ mainly differs from connecting member 4 bycomprising a ring nut 71′, which performs the same function as ring nut71, but is clicked on to the outside of main member 10.

[0064] More specifically, ring nut 71′ comprises a substantiallycylindrical annular main portion 100 identical to ring nut 71 and housedbetween portion 32 of lateral wall 26 of valve member 11 and main member10; and an annular peripheral portion 101 connected at one end to mainportion 100 and clicked on to the outer surface of main member 10.

[0065] Being clicked on to main member 10, ring nut 71′ is free torotate about axis A, but is axially fixed.

[0066] Connecting member 4′ also comprises a ring nut 70′, which isidentical to ring nut 70, is fitted in angularly fixed, axially slidingmanner to portion 32 of lateral wall 26 of valve member 11, and islocated between ring nut 0.71′ and bars 60.

[0067] In this case, too, ring nuts 70′ and 71′ are connected to eachother by respective complementary face surfaces 80, 81.

[0068] Connecting member 4′ also differs from connecting member 4 bypush ring 65 defining, along its radially inner and outer surfaces,respective splined couplings 102, 103 for connection to valve member 11and main member 10.

[0069] At the free end facing away from disk-shaped wall 25, valvemember 11 comprises four parallelepiped-shaped projections 104, which,in the second work position of valve member 11, engage respectivecomplementary recesses 105 formed in the radially inner surface of ringnut 71′, thus preventing any rotation of ring nut 71′ as long as valvemember 11 is in the second work position. That is, push-button member 51must be operated first to disconnect connecting member 4′ and endpiece5.

[0070] The advantages of connecting members 4, 4′ according to thepresent invention will be clear from the foregoing description.

[0071] In particular, ring nuts 70, 70′, 71, 71′ and the way in whichthey are retained to valve member 11 and to main member 10 rule out anypossibility of stop mechanism 16 being deactivated before orsimultaneously with release of stop mechanism 15, thus bypassing thesafety function of coupling 1.

[0072] In the case of connecting member 4, in fact, ring nut 71 isprevented from being rotated until grooves 79 of ring nut 71 arereleased by respective projections 76 on main member 10—which onlyoccurs when valve member 11 is in the first work position, i.e. whenconduit 2 is separated in fluidtight manner from the outside. Moreover,any inadvertent axial retention of ring nut 71 by the user whenoperating push-button member 51 has no effect whatsoever on bars 60,and, therefore, can in no way result in simultaneous release of endpiece5.

[0073] Similarly, in the case of connecting member 4′, ring nut 71′ isprevented from being rotated until projections 104 on valve member 11are released from respective recesses 105 on ring nut 71′—which onlyoccurs when valve member 11 is in the first work position (FIG. 12).

[0074] Clearly, changes may be made to connecting members 4, 4′according to the present invention, without, however, departing from thescope of the accompanying claims.

1) A connecting member (4, 4′) connectable to a first conduit (2) forconducting a pressurized operating fluid, and fittable releasably to anendpiece (5) of a second conduit (3) for conducting said operatingfluid, so as to define a fast-fit safety coupling (1); said connectingmember (4, 4′) having a longitudinal axis (A) and comprising: asubstantially tubular main member (10) connectable to said first conduit(2); a slide valve member (11) fitted inside said main member (10) so asto slide axially between a first work position wherein said valve member(11) separates said first conduit (2) in fluidtight manner from theoutside, and a second work position permitting fluid flow between saidfirst and said second conduit (2, 3); first retaining means (18) forreleasably connecting said endpiece (5) to said valve member (11);second retaining means (17) for releasably connecting said valve member(11), in said second work position and connected to said endpiece (5),to said main member (10); and control means (70, 70′, 71, 71′, 72, 54)for disconnecting said connecting member (4, 4′) and said endpiece (5)by successively releasing said second retaining means (17)—thus movingsaid valve member (11) into said first work position and permittingoutflow of the operating fluid between said main member (10) and theendpiece (5)—and said first retaining means (18); said control means(70, 70′, 71, 71′, 72, 54) comprising a first actuating member (70, 70′)fitted in angularly fixed manner to said valve member (11) and movableaxially with respect to the valve member (11) in opposition to elasticreturn means (66) to release said first retaining means (18);characterized in that said control means (70, 70′, 71, 71′, 72, 54)comprise a second actuating member (71, 71′), which is axially fixed androtatable with respect to said valve member (11) at least in said firstwork position of the valve member (11); and cam transmission means (72)interposed between said first and said second actuating member (70, 70′,71, 71′) and for converting rotation of said second actuating member(71, 71′) into axial displacement of said first actuating member (70,70′) in opposition to said elastic means (66). 2) A connecting member asclaimed in claim 1, characterized in that said valve member (11) has aninner cavity (27) engaged, in use, by said endpiece (5); and in thatsaid first retaining means (18) comprise a number of engaging members(60), which are mounted to slide inside respective seats (61) formed ina lateral wall (26) of said valve member (11) defining said cavity (27),are pushed by said elastic means (66) into a coupling position engagingan annular groove (7) on said endpiece (5), and are moved into a releaseposition releasing said groove (7) on said endpiece (5) by the thrustgenerated by said first actuating member (70, 70′) moving axially inopposition to said elastic means (66). 3) A connecting member as claimedin claim 2, characterized in that said engaging members (60) are locatedbetween said elastic means (66) and said first actuating member (70,70′). 4) A connecting member as claimed in claim 3, characterized inthat said engaging members comprise two transverse bars (60) extendingparallel to each other on diametrically opposite sides of saidlongitudinal axis (A). 5) A connecting member as claimed in any one ofthe foregoing claims, characterized by comprising disabling means (76,79; 104, 105) for preventing rotation of said second actuating member(71, 71′) and which are selectively deactivated in said first workposition of said valve member (11). 6) A connecting member as claimed inclaim 5, characterized in that said disabling means comprise splinedcoupling means (79, 76) between said second actuating member (71) andsaid main member (10), and which are deactivated by movement of saidvalve member (11) into said first work position. 7) A connecting memberas claimed in any one of the foregoing claims, characterized in thatsaid cam transmission means (72) comprise a first and a second surface(80, 81) mating with each other and formed on said first and said secondactuating member (70, 70′, 71, 71′) respectively. 8) A connecting memberas claimed in claim 7, characterized in that said first surface (80)comprises a number of troughs (82), and said second surface (81)comprises a number of crests (84) corresponding in shape to that of saidtroughs (82). 9) A connecting member as claimed in claim 8,characterized in that said troughs (82) and said crests (84) haverespective V-shaped profiles. 10) A connecting member as claimed inclaim 8 or 9, characterized in that said first and said second surface(80, 81) comprise a number of flat portions (83, 85) alternating withrelative said troughs (82) and relative said crests (84) respectively.